Warnings that require no action can be ignored. These warnings display in a dialog in the lower-right corner of the interface. When the warning displays, the element or elements that cause it are highlighted in a user-definable color. See , for information about changing this color.
Unlike error messages, warning messages do not prohibit the current action. They just inform you of a situation that may not be your design intent. You can choose to correct the situation or ignore it. Revit maintains a list of warning messages that are displayed and ignored while you are working. The Warnings tool lets you view the list at your convenience to determine if the conditions described in the warnings still exist.